(Stranger / Eraser)
GBL from THF using trichloroisocyanuric acid
(Rated as: excellent)
From J.Org.Chem 31, 3836 (1966):
"In order to moderate the reaction the reaction flask was placed in an ice bath. To 60 ml (53.28 g, 0.74 mole) of THF, containing 6 ml of water, was added 23.24 g (0,10) mole of trichloroisocyanuric acid at such a rate as to mantain a gentle reflux. Upon addition of the first amount of , a yellow color appeared and quickly faded. A white precipitate formed immediately. After all the trichloroisocyanuric acid was added, the reaction mixture was allowed to stir overnight. Cyanuric acid precipitated almost quantitatively and was removed by filtration. (...)the filtrate was combined with 60 ml of ether and extracted 3 times with 20 ml portions of 5% aqueous sodium bicarbonate. The ether layer was distilled, and found to contain only THF. The water layer was acidified with aqueous hydrochloric acid, and the water and hydrochloric acid were removed by azeotropic distillation with benzene. The benzene was removed by distilation , leaving 2.55 g (19%) of gamma-butyrolactone."
The yields are not very good, and the reaction workup has to be changed fot this to be practical, but trichloroisocyanuric acid is very easy to get in big quantities.
And here's a review of the use of trichloroisocyanuric acid in organic chemistry, including addition of HOCl to alkenes, oxidation of sec-alcohols to ketones, and some other chlorination and oxidation reactions:
Org. Proc. Res. Dev. 6, 384, 2002.